Feeding mechanisms for sewing machines



June 10, 1958 E. J. HERBST 2,838,018

FEEDING MEcHANrsMs FOR SEWING MACHINES Filed July 9, 1956 2 Sheets-Sheet 1 a 2 N Qu- N IO ro no l/vvEN TOR Edward J Herbs @Y 3 ZZMTORNEY 'June 1o, 1958 E. J. HERBST 2,838,018

FEEDING MEcHANIsMs FOR SEWING MACHINES Filed July 9, 195e 2 Sheets-Sheet 2 24 /f/ n K y INVENTOR. Edward JHerbs WITNESS BY m44 g4/W14 6MM ATTORNEY nited i States Patent FEEDIN G MECHANISMS FOR SEWING MACHINES Edward J. Herbst, South Plainfield, N. I., assigner to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application July 9, 1956, Serial No. 596,687 3 Claims. (Cl. 112-210) The present invention' relates to sewing machines, and particularly to oscillating shuttle type sewing machines, and has for a primary object to provide in such a machine, an improved feeding mechanism.

As disclosed in the Johnson Patent No, 2,761,402, Sept. 4, 1956, the feeding mechanism of an oscillating shuttle type sewing machine includes a feed-lift shaft that is actuated by a fork that embraces a feed cam on the bed shaft which is oscillated by a crank arm and pitman from a crank on the main shaft, and the shuttle shaft is oscillated by a fork integral with the and connected to a slide on a crank arm on the shuttle shaft. It has been found that feeding in such a machine can be improved by delaying the feeding cycle. However, the timing of the shuttle is very critical and in such a construction, the timing of the feed lift is dependent upon the timing of the shuttle. feeding cycle is fixed by the desired maximum length of stitch and thus the time that the feed-lift is operative cannot be varied. Therefore, merely adjusting the feedlift cam on the bed shaft is impossible since the feedlift must occur during the time that the bed shaft is turning in a direction to reverse the shuttle. If the feedlift were merely delayed by adjusting theAfeed-cam, the bed shaft would begin turning in the opposite direction to advance the shuttle and at the same time feed-lift before the desired interval of feed-lift has been obtained, thus reducing the feeding cycle.

In accordance with the present invention, there has been provided a separate drive for the feed-lift whereby it is actuated from the main shaft independently of the bed shaft, the timing of which is determined by the shuttle requirements, and there has been provided aA novel construction for accomplishing this operation, which construction is simple, efficient, durable and economical, and can be adaptedto present designs.

Having in rnind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

Fig. 1 is a fragmentary vertical sectional view of the standard end of a sewing machine embodying the present invention.

Fig. 2 is a sectional View taken substantially on the line 22 of Fig. 1.

Fig. 3 is a fragmentary bottom plan View of the sewing machine of Fig. 1.

Fig. 4 is a detail sectional view taken substantially on the line 4-4 of Fig. 3.

The sewing machine embodying the present invention is herein disclosed only insofar as is believed to be necessary for a complete understanding of the invention. It

bed shaft reverse the The duraion of the t lor pintles 23 in depending lugs will be understood that the portions not illustrated may be of any suitable construction, one preferred form being disclosed in the above mentioned Johnson Patent No. 2,761,402.

A portion of the machine frame is illustrated in the drawings, including a bed 1 from which rises the standard 2 carrying the bracket arm 3. Journalled longitudinally of the bracket arm 3 is the main shaft 4 having a hand wheel and belt pulley 5 mounted upon the exposed end thereof and by means of which power is delivered to the machine.

Journalied by cone-shaped end bearings or pintles 7 in depending lugs 6 and 6a in the bed 1 is a bed shaft S which is arranged parallel to the main shaft 4. Integral with the bed shaft 8 is a crank arm 9 which is pivotally connected to the end of a pitman 10 having a strap portion 11 at its upper end embracing a rotary actuator in the form of an eccentric 12 0n the main shaft 4, whereby upon rotation of the main shaft 4 oscillation will be imparted to the bed shaft 8.

lournalled at one end in the bearing 6 in the bed of the machine andarranged parallel to the bed shaft v8 is an oscillating shuttle shaft 13 having secured on the end thereof by a set screw 14, Fig. 3, a hub 15 of a crank arm 16 which pivotally carries at its end a slide block 17 that is disposed between the tines of a fork 18 integral with the bed shaft 8. Thus, upon oscillation of the bed shaft 8, oscillation is imparted to the shuttle shaft 13 in the usual manner.

The feeding mechanism of the machine includes a feed-advance shaft 19 journalled longitudinally of the bed 1 by cone-shaped end bearings or pintles 20 in depending lugs as at 21, and a feed-lift shaft 22 journalled longitudinally of the bed 1 by cone-shaped end bearings as at 24. While not illustrated, it will be understood that the feed-lift shaft 22 and feed-advance shaft 19 are adapted'upon oscillation to actuate a feed-bar in the usual manner to impart feeding motions thereto. The feed advance and return motion, and thus the stitch length, is determined by the feedadvance shaft 19 and the rising and falling motion of the feed-dog is determined by the feed-lift shaft.

Oscillations, which are adjustable as to magnitude, are imparted to the feed-advance shaft 19 by a pitman 25 pivotally connected at its lower end to a crank arm 26 integral with the feed-advance shaft 19. At its upper end the pitman has a fork 27 that cooperates with a rotary actuator in the form of a cam 28 secured to the main shaft 4. To convert the oscillation imparted to the pitman 25 by the cam 28 into endwise reciprocation of theV piunan, the latter carries a slide block 29 pivotally mounted thereon and riding in a slideway 30 in a pivot block-31 that is pivoted to a lug 32 on the frame by a screw 33. The inclination of the slideway 30 is manually varied by a handle 34 on the pivot block 31 that extends through a slot 35' in the front of the machine and cooperates with suitable indicia (not shown) on a plate 36 to indicate the setting of the feed advance mechanism.

Oscillations are imparted to the feed-lift shaft 22 by a crank fork 37 integral therewith and cooperating with a feed cam 38 journalled on a reduced end portion 39 of the bed shaft 8. The cam 38 includes an integral sleeve 40 on which is secured, by a set screw 41, a hub 42 having a crank arm 43 that is pivotally connected to the lower end of a pitman 44 having at its upper end a strap 45 that embraces a rotary actuator in the form of an eccentric 46 on the main shaft 4.

It will be seen that by the above construction, the actuation of the feed-lift mechanism is independent of the actuation of the shuttle mechanism and it can be adjusted independently of the shuttle mechanism. Thus, timing of' the shuttle, which is accomplished' by adjustment of the eccentric 12 on the main shaft 4, does not affect the timing of the feed-lift mechanism which may be accomplished by adjustment of the eccentric 46'. on the main shaft 4. rFhecrank arm 43 can. also be adjusted on the sleeve 40. At the same time, the feed path can be varied by changing the configuration of the feed cam 38"and by adjusting it angularly on the reduced end.' portion 39 of the bed shaft 8.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred' embodiment of my invention which is for purposes of illustration only and not to be constructed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended' claims.

Having thus described the nature of the invention, what I claim herein'is:

1. In a sewing machine having a frame including a bracket arm and'a bed, a main shaft journalled longitudinally of said bracket arm, a bed shaft journalled in said bed, means including a first rotary actuator on said main shaft for imparting'oscillation to said bed shaft upon rotation of said main shaft, stitch-forming mechanism including ay shuttle shaft journalled in said bed, operative `connections between saidbed shaft and said shuttle shaft for imparting oscillation to said shuttle shaft upon oscillation of said bed shaft, feeding mechanism for advancing work past the point of stitch formation and including a feed-advance shaft and a feed-lift shaft journalled in said bed, adjustable means including a second rotary actuator on said main shaft for imparting oscillation to said feed-advance shaft upon rotation of said main shaft, a feed-lift cam journalled on said bed shaft, means including a third rotary actuator on said main shaft for imparting oscillation to said. cam upon rotation of said main shaft, and operative connections between said cam and said feed-lift shaft for imparting oscillation to said feed-lift shaft upon oscillation of said cam.

2. In a sewing. machine having a frame including a bracket arm and a bed, a main shaft journalled longitudinally of said bracket arm, a bed shaft journalled in said bed, means including a first rotary actuator on said main shaft for imparting oscillation to said bed shaft upon rotation of said main shaft, stitch-forming mechanism including a shuttleshaft journalled in said bed, op-

erative connections between said bed shaft and said shuttle shaft for imparting oscillation to said shuttle shaft upon oscillation of said bed shaft, feeding mechanism for advancing work past the point of stitch formation and including a feed-advance shaft and a feed-lift shaft journalled in said bed, adjustable means including a second rotary actuator on said main shaft for imparting oscillation to saidfeed-advance shaft upon rotationof said main shaft, a feed-lift cam journalled on said bed shaft, a crank arinsccured to said cam, athird rotary actuator on said main shaft, a pitman pivotally connected to said crank arm and cooperating with said third rotary actuator for imparting oscillation to said cam upon rotation of said main shaft, and a fork on` said feed-lift shaft and cooperating with said cam to impart oscillation to said feed-lift shaft upon oscillation of said cam.

3. ln a sewing machine having a frame including a bracket arm and af bed, a main shaft journalled longitudinally of. said bracket arm, a bed-shaft journalled in said bed, meansincluding a first rotary actuator on said main shaft for imparting oscillation to said bed shaft upon rotation of said main shaft, stitch-forming mechanism including a shuttle shaft journalled in said bed, operative connections between said bed shaft and said shuttle shaft for imparting oscillation to said shuttle shaft upon oscillation of said bed shaft, feeding mechanism for advancing work past the point of stitch formation and including a feed-advance shaft and a feed-lift shaft journalled in said bed, adjustable means including a second rotary actuator on said main` shaft for imparting oscillation to said feed-advance shaft upon rotation of said main shaft a feed-lift cam and a sleeve integral with said feed-lift.

carn journalled on said bed shaft, a hub secured on said sleeve for angular adjustment and having a crank arm,

" a third rotary actuator on said main shaft, a pitman pivotally connected to said crank arm and cooperating with said third rotary actuator for imparting oscillation to said cam upon rotation of said main shaft, and a fork on said feed-lift shaft and cooperating with said cam to impart oscillation to said feed-lift shaft upon oscillation of said cam.

References Cited in the file-of this patent UNITED STATES PATENTS 401,182 Leilich Apr. 9, 1889 1,118,271 Diehl et al. Nov. 24, 1914 1,934,373 Peets Nov. 7, 1933 

